Are you overtraining your horse? You might soon be able to answer this question with a simple home test. A team of Dutch researchers is currently trying to find the specific biomarkers that would make such a test possible.

The team’s most recent research, which focused on pinpointing biomarkers in muscle tissue, not only revealed signs of horses overworking but also showed how devastating overtraining can be, said Marinus te Pas, PhD, senior researcher of genomics and bioinformatics in the Animal Breeding and Genomics Centre at Wageningen UR Livestock Research, in Lelystad.

“The present study was a first step that showed that overtraining adversely affected both muscle tissue (function) and health-threatening functions like stress—including apoptosis (programmed death) of cells—and immune functions,” said te Pas. “We now know the genes responsible, and we can use this information to develop a simple test (based on urine, blood, or saliva samples).”

Te Pas and his fellow researchers—Inge Wijnberg, DVM, PhD, and Han van der Kolk, DVM, PhD, both of Utrecht University in The Netherlands—followed two groups of young Standardbred geldings in training over an 18-week period. One group of horses followed a “regular” training protocol, while the other group followed an “intense” training protocol followed by a four-week period of “detraining” (a very low-intensity protocol). In common practice, “detraining” is intended to “undo” the harmful effects of intense training, te Pas said.

The researchers performed muscle biopsies on each horse